<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>Flexbox: Simple Test</title>
        <style type="text/css">
            * { margin: 0; padding: 0; }
            body {
                width: 800px;
                height: 600px;
                padding: 20px;
                background: #ecf0f1;
            }
            .container {
                display: flex;
                width: 100%;
                height: 100px;
                background: white;
                border: 2px solid black;
            }
            .item1 {
                flex-grow: 1;
                background: #e74c3c;
            }
            .item2 {
                flex-grow: 2;
                background: #3498db;
            }
            .item3 {
                flex-grow: 3;
                background: #2ecc71;
            }
        </style>
    </head>
    <body>
        <div class="container">
            <div class="item1" style="flex-grow: 1;"></div>
            <div class="item2" style="flex-grow: 2;"></div>
            <div class="item3" style="flex-grow: 3;"></div>
        </div>
    </body>
</html>
